Intake port construction for rotary mechanisms



Sept. 10, 1963 H. N. PRICE ETAL INTAKE PORT CONSTRUCTION FOR ROTARYMECHANISMS 3 Sheets-Sheet 1 Filed June '7, 1960 INVENTORS HARRY N- PRICEEXANDER H- RAYE Mp ym, Fww m,fiurfim; m

ATTORNEYS 56 d6 55 AL Sept. 10, 1963 H. N. PRICE ETAL INTAKE PORTCONSTRUCTION FOR ROTARY MECHANISMS Filed June 7, 1960" a .sheets -she et2 FIG. 3' 72 I INVENTORS HARRY N. PRICE ALEXANDER H- RAYE p 1963 H. N.PRICE ETAL 3,103,208

INTAKE PORT CONSTRUCTION FOR ROTARY MECHANISMS Filed June 7, 1960' 3Sheets-Sheet 3 INVENTORS HARRY N- PRICE ALEXANDER H- RAYE BY Marylin,myb flarfim I pul .ATTORNEYS United States Patent 3,103,208 INTAKE PURTCONSTRUCTION FOR ROTARY MECHANISMS Harry N. Price, East Paterson, andAlexander H. Raye,

Paramus, N.J., assignors to Curtiss-Wright Corporation,

a corporation of Delaware Filed June 7, 1960, Ser. No. 34,492 3 Claims.(Cl. 123-8) The present invention relates to intake port constructionsfor rotary mechanisms, and more particularly to an intake portconstruction which improves the fluid sealing characteristics of themechanism and helps to insure relatively trouble-free and smoothfunctioning of the seals.

Although this invention is applicable to and useful in almost any typeof rotary mechanism, such as combustion engines, fiuid motors, fluidpumps, compressors, and the like, it is particularly useful in rotatingcombustion engines. To simplify and clarify the explanation of theinvention, the description which follows will, for the most part, berestricted to the use of the invention in a rotating combustion engine.It will be apparent from the description, however, that with slightvariations which would be obvious to a person skilled in the art, theinvention is equally applicable to other types of rotary mechanisms. Thepresent invention is particularly useful in rotary mechanisms of thetype which comprise an outer body having an axis, axially-spaced endwalls, and a peripheral wall interconnecting the end walls. In suchrotary mechanisms the inner surfaces of the peripheral wall and end Iwalls form a cavity, and the mechanism also includes an inner body orrotor which is mounted within the cavity between its end walls.

The axis of the inner body or rotor is eccentric from and parallel tothe axis of the cavity of the outer body, and the rotor hasaxially-spaced end faces disposed adjacent to the end walls of the outerbody, and a plurality of circumferentially-spaced apex portions.rotatable relative to the outer body, and its apex portionssubstantially continuously engage the inner surface of the outer body toform a plurality of working chambers which vary in volume during engineoperation, as a result of relative rotation between the rotor and outerbody.

The inner surface of the peripheral wall of the'outer body has amulti-lobed profile which is preferably an epitrochoid and the number oflobes of this epitrochoid is one less than the number of apex portionsof the inner body or rotor.

By suitable arrangement of ports, such rotary mechanisms may be used asfluid motors, compressors, fluid pumps, or internal combustion engines.The invention is of particular importance when employed with a rotarymechanism which is designed for use as a rotating combustion engine,and, accordingly, will be described in combination with such an engine.As the description proceeds, however, it will be apparent that theinvention is not limited to this specific application.

When the rotary mechanism is designed for use as a rotating combustionengine, such engines also include an intake passage means foradministering a fuel-air mixture to the variable volume workingchambers, an exhaust passage means communicating with the workingchambers, and suitable ignition means so that during engine operationthe working chambers of the engine undergo a cycle of operation whichincludes the four phases of intake, compression, expansion, and exhaust.This cycle of operation is achieved as a result of the relative rotationof the inner body or rotor and outer body and for this purpose both theinner body or rotor or outer body may rotate at different speeds, butpreferably the inner body or rotor rotates 'while the router body isstationary.

The rotor is bers should be sealed, and therefore an effective seal isprovided between each rotor apex portion and the inner surface of theperipheral wall of the outer body, as well as between'the end faces ofthe rotor and the inner surfaces of the end Walls of the'outer body.

Between the apex portions of its outer surface the rotor has a contourwhich permits itsrota-tion relative to the outer body free of mechanicalinterference with the multilobed inner surface of the outer body. Themaximum profile which the outer surface of the rotor can have betweenits apex portions and still be free to rotate without interference isknown as the inner envelope of the multi-lobed inner surface, and theprofile of the rotor which is illustrated in the accompanying drawingsapproximates this inner envelope.

For purposes of illustration, the following description will be relatedto the present preferred embodiment of the engine in which the innersurface of the outer body defines a two-lobed epitrochoid, and in whichthe rotor or inner body has three apex portions and is generallytriangular in cross-section but has curved or arcu ate sides.

'It is not intended that the invention be limited, however, to the formin which the inner surface of the outer body approximates a two-lobedepitrochoid and the inner body or rotor has only three apex portions. Inother embodiments of the invention the inner surface of the outer bodymayhave a different plural number of lobes with a rotor having one moreapex portion than the inner surface of the outer body has lobes.

The sealing means which provides sealing between'the end faces of therotor and the end walls of the outer body, in the present embodiment,extend along the end faces of the rotor between its apex portions, andare substantially parallel to the outer peripheral edges of the rotor.These seals are carried in the rotor and normally engage the end wallsof the outer body in sliding, gaspresent invention is applicable torotary mechanisms which i employ a side intake port in at least one ofthe outer body end walls .as opposed to an intake port in the peripheralwall of the outer body.

When the end face seals, during rotation of the rotor relative to theouter body, move across the intake port, .or span it, during a portionof the rotor travel relative to the outer body, the seals tend to bowoutward towards the end walls so that they extend into the intake cavityor port. The seals are caused or tend to bow out'in this manner becauseof mechanical means used to exert an outward pressure on the seals tokeep them in sealing contact with the end walls of the outer body.

Obviously then, during the final portion of the intake phase of theengine cycle, the portion of the seal which extends into the intakecavity or port will tend to come into engagement with the closing edgeof the intake port formed between the intake port and the end wall ofthe outer body. This relationship presents a problem in enginefunctioning, since repeated contact between the edge of the seal and theclosing edge of the intake port, at the least, leads to excessive anduneven wear of the seal and the edge of the port, and at the'worst, canlead to seal breakage through shearing engagement between the seal andthe edge of the port, and seal breakage may, in turn, even lead toengine failure.

The instant invention is primarily directed to improving therelationship between the contour of the edge of the intake port and thecontour of the seal to avoid the 3 undesirable eifects which areotherwise created when the seal bows, even slightly, into the intakeport.

It is known to those skilled in the internal combustion engine art thatthe fuel-air mixture which is drawn into the working chamber during thelast stage of the intake phase is normally a particularly fuel-richmixture. It is also a Well-known desideratum of internal combustionengines that the closing of the intake port should be 'accomplished bymoving from a large area of opening to a closed port or zero areacondition as quickly as possible, and this desideratuin may be termed aquick closing characteristic. i

This quick closing characteristic can be achieved most eflicaciously byproviding a contour for the closing edge of the intake port which issubstantially coincident with the peripheral edge of the rotor when therotor edge is moving over the port. Since the end face seal is approximately parallel to the rotor edge and only .a short distanceradially inward on the rotor from the edge, the seal will also besubstantially coincident with such a closing edge contour as it movesover the port edge immediately behind the rotor edge. Although such aclosing edge contour provides the ideal attainable quick-closingcharacteristic, it is undesirable from the standpoint of sealdurability. I

As explained previously, if the closing edge of the intake port and theend face seal have virtually identical and aligned contours, the seal asit moves over the edge and re-engages the'end wall of the outer body insealing contact will be subjected to .a shock and shearing action eachtime the port is closed.

In operation of a rotating combustion engine, the last portion of thefuel-air mixture to enter the Working chamber during intake is afuel-rich mixture. Since fuel is heavier than air, it lags, behind theair as it flows into the chamber through the intake port. Because ofthis phenomenon, thelast portion of the mixture to enter the chamberwill be fuel-rich compared to the first portion of the mixture. Also,since the compression phase has commenced by the time the port hasclosed, the last fuelrich portion of the mixture to enter the chamber isnot appreciably dispersed or diffused through the chamber but tends toremain in the same general location with respect to the working face ofthe rotor.

Accordingly, it ispossible to relate the position of the fuel-richmixture at the end of the intake phase to the position of the ignitionmeans when the working face moves from its position at the end of theintake phase to its firing posit-ion opposite the ignition means, andthereby to insure that this fuel-rich mixture will be opposite to oradjacent to the ignition means at the time of firing.

It is, accordingly, a primary object of the present invention to providemeans to insure quick closing of the intake port and at the same timeavoid any excessive wear or shock to the rotor end face seal when itcomes into contact with the closing edge of the intake port.

It is another object of the instant invention to provide means forgradually picking up or removing the rotor end face seal from itsbridging position across the intake port or cavity.

It is another object of the present invention to provide means togradually pick up or remove the rotor end face seal from the intake portor cavity from the outside moving inwardly toward the axis of the outerbody.

It is another object of the present invention to provide means forgradually picking up or removing the rotor end face seal from the intakeport or cavity from the inside moving outwardly away from the axis ofthe outer body.

Another object of the instant invention is to provide means forgradually picking up or removing the rotor end face seal from the intakeport or cavity moving from both the inner and outer ends of the intakeport closing edge toward an intermediate portion of the closing edge.

It is a further object of the instant invention to provide means toinsure that an enriched fuel-air mixture is located opposite the sparkplug location when ignition takes place.

It is a still [further object of the instant invention to provide meansto yield better ignition characteristics in a rotating combustion engineand faster and more constant flame propagation velocities to givesmoother operation and improve combustion.

In the description which follows it is to be recognized that, inpractice, either the outer body or the inner rotor may rotate while theother member remains fixed or stationary, or both members may rotate aslong as there is relative rotation between them to provide variablevolume working chambers.

- in the description of the present preferred embodiment, for purposesof clarity, the invention will be described with reference to a rotarymechanism in which the outer body or housing is fixed or stationary andthe inner body is rotatable, or a rotor.

For purposes of definition in the specification and claims, the termoutside refers to an area or point near, adjacent to, or in thedirection of the peripheral wall of the outer body; while the terminside refers to an area or a point located near, adjacent to, or in thedirection of the axis or center of the outer body.

Broadly described, the present invention provides means for graduallypicking up or removing the rotor end face seal from a bridged positionacross the intake port or cavity and placing it in continuous contactposition against the inner sunface of the end wall of the outer bodywithout appreciably sacrificing the quick-closing characteristic of theintake phase; and the invention also provides means to insure that afuel-rich l uel-air mixture is located opposite the ignition means atthe time of firing.

Additional objects and advantages of the invention will be set forth inpart in the [description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention, theobjects and advantages being realized and attained by means of theinstrumentalities and combinations particularly pointed out in theappended claims.

The invention consists in the novel parts, constructions, arrangements,combinations, and improvements shown and described.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one embodiment of (the inventionand, together with the description, serve to explain the principles ofthe invention.

Of the drawings:

FIG. 1 is a side elevation of the mechanism with one end wall of theouter body removed to show the rotor positioned within the outer body.Portions of the rotor and outer body are shown partially in section;

FIG. 2 is a central vertical section of the mechanism taken along theline 2-2 of FIG. 1 in which the rotor and outer body are shown insection while the shatft and eccentric are shown without sectioning;

FIG. 3 is a fragmentary view showing the intake port section of theinner surface of the outer body and a portion of the rotor in theposition it occupies with respect to the intake port shortly afterclosing of the intake pont. This view shows the conditions which wouldexist in a rotary mechanism without the benefits of the presentinvention;

FIG. 4 is an enlarged (fragmentary sectional view taken along the line4-4 of FIG. 3 to illustrate the deleterious effects which may occur tothe rotor end face sealing means in a rotary mechanism to which thepresent invention has not been applied. For clarity of explanation, andto permit visual apprehension of operative eifects, certain portions ofthis figure have been (grossly exaggerated;

FIG. 5 is a fragmentary view showing the intake port section of theouter body and a portion of the rotor in the position it occupies withrespect to the intake port at a time just prior to closing of the intakeport. This View illustrates by means of various types of broken andphantom lines, three different ways in which the beneficial results ofthe present invention may be achieved in practice. For ease and clarityof explanation, certain portions of this view have also beenexaggerated;

FIG. 6 is a fragmentary and partially schematic view illustrating how afuel-rich fuel-air mixture may be placed in a location substantiallyopposite the ignition means in a rotating combustion engine at the timewhen ignition takes place.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory but arenot restrictive of the invention.

Reference will now be made in detail. to the present preferredembodiment of the invention, an example of which is illustrated in theaccompanying drawings.

As shown in FIG. 1, a generally triangular rotor 10 having arcuate sidesis eccentrically supported for rotation within an outer body 12.Although in the illustrative embodiment shown in the drawings the outerbody 12 is fixed or stationary, a practical and useful form of theinvention may be constructed in which both the outer body and rotor arerotary, but the eccentric is stationary; in this latter form of theinvention the power shaft is driven directly by the rotation of theouter body and the inner rotor rotates relative to the outer body.

A still third form of the invention is possible in which the rotorremains fixed or stationary and the outer body and eccentric arerotatable.

As shown in FIGS. 1 and 2, the outer body 12 has a cavity, and thecavity has an axis 16. The rotor 16 is mounted for rotation within thecavity on an axis 14 which is parallel to and laterally spaced from theaxis 16. The profile of the curved inner surface 18 of the outer body 12has basically the form of an epitrochoid. The center of this epitrochoidis on the axis 1 6, and the epitrochoid includes two arched lobedefining portions, or lobes.

An intake port 20 is arranged to communicate with one lobe of theepitrochoidal inner surface 13, and an exhaust port 22 is arranged tocommunicate with the other lobe.

The center of the epitrochoid which is described by the projection ofthe inner surface 18 on a plane transverse to the axis 16 of the outerbody 12 coincides with the axis 16. "there are two points of leastradius on the epitrochoid from its center 16. A line which connectsthese two points of least radius and passes through the center of theepit-rochoid is designated its minor axis 2 6. Similarly, theepitroohoid has two points of greatest radius, and a line connectingthese two points and passing through the center of the epitrochoid isdesignated its major axis 24.

As embodied, it is apparent that the minor axis 24 divides theepitrochoid into two halves. For convenience, the half or lobe whichcommunicates with the exhaust port 22 may be called the exhaust lobe andthe half or lobe which communicates with the intake port 20 may becalled the intake lobe.

As embodied, the generally triangular shape of the rotor 19 correspondsin its configuration to the inner envelope or the maximum profile of therotor which will permit interferenceifree rotation of the rotor 10within the outer body 12.

As shown in FIGS. 1 and 2, the outer body 12, which is stationary inthis embodiment, comprises two end walls 28 and 30 and a peripheral wall3'2 interconnecting these end walls. A shaft 34 is rotatably supportedby the end walls 28 and 30 of the outer body 12 by means of conventionalbearings, and the axis of the shaft 34 is coincident with the axis '16of the outer body 12.

An eccentric 36 is rigidly mounted on and forms an integral part of theshaft 34; the axis of the eccentric 36 is eccentric from and parallel tothe shaft axis 16. The rotor 14) is rotatably supported upon theeccentric 36, and the central axis of the eccentric 36 is coincidentwith the axis Mott the rotor 10.

As shown in FIG. 1, the rotor 10 includes three apex portions 38 whichcarry radially movable sealing memhers 4d. The sealing members 40 are insubstantially continuous sliding, gas-sealing contact the inner surface18 of the outer body 12, as the rotor 10 rotates within and relative tothe outer body 12.

'By means of the relative rotation of the rotor 10 to the outer body 12,three variable volume working chambers 42 are formed between the outerperipheral working faces 44 of the rotor 10 and the inner surface 18 ofthe outer body 12. As embodied in FIG. 1, the rotation of the rotorrelative to the outer body is counterclockwise and is indicated by anarrow.

A spark plug 46 is mounted in the peripheral wall 32 of the outer body'12, and at the appropriate time in the engine cycle, spark plug 46provides ignition for a compressed cornbustible mixture which uponexpansion drives the rotor in the direction of the arrow.

The eccentricity 2 (FIG. 2) of the rotor axis 14 from the outer bodyaxis 16 acts as a crank arm or moment arm to convert the energy of theexpanding gases into torque on the shaft 34.

As the rotor 10 rotates, fresh combustible gases are drawn into theworking chambers 42 through the intake port 20. These combustible gases,or the fuel-air mixture, are then successively compressed, ignited,expanded, and finally exhausted through the exhaust port 22.

All four successive phases of the engine cycle: intake, compression,expansion, and exhaust, take place within each one of the variablevolume Working chambers each time the rotor completes one revolutionwithin the outer body; or for each revolution of the rotor, the enginegoes through one complete cycle.

Cut-away portions or channels 45 are provided in the working faces 44 ofthe rotor to permit the free passage of combustion gases between theintake lobe and the exhaust lobe of the inner surface 18 of the outerbody when the rotor is in or near the position of top dead centercompression.

A bearing 43 is provided between the bearing bore of the rotor 10 andthe eccentric 3 6. As shown most clearly in FIG. 2, aninternally-toothed or ring gear 50 is integrally attached to the bearing48, and both the bearing 48 and ring gear 50 are fixed to the rotor 10.

This ring gear 50 is in meshing engagement with an externally-toothedgear or pinion 52 which is rigidly attach-ed to the outer body 12. Thegear ratio between the rotor ring gear 5% and the outer body gear orpinion 52 is 3:2 so that for every revolution of the rotor 10 about itsown axis 14, the shaft 34 rotates three in the same direction.

The purpose of the gearing between the rotor 10 and the outer body 12 isto register or index the rotor in its position relative to the outerbody, and to relieve the positioning load from the apex portions 38 andsealing members 40 of the rotor which would otherwisebear the load ofdetermining the registration of the rotor with respect to the outerbody. The gearing, thus, does not function to impart torque to the shaft34-, this function being accomplished through the moment arm of theeccentricity e of the eccentric 36 or rotor axis '14.

In accordance with the invention, means are provided for admitting thefuel-air mixture into the intake chamber of the engine. As embodied,this means preferably takes the form of a passage :or cavity in an endwall which terminates in an intake port in the intake lobe of theepitrochoidal inner surface of the outer body.

This intake passage and its port may be located in either or both endwalls of the router body. In the aioaaos form of the inventionillustrated in the accompanying drawing (FIG. 1), this means is shown asthe intake port 20 in the end wall 3%.

It is apparent, however, that a second intake port could be locatedopposite the intake port 20 in the other end Wall 30. Also as embodied,and shown in FIGS. 1, 3, and 5, the intake port has roughly the shape ofa triangle.

In the present embodiment, the base or longest leg of the triangle isgenerally inside or toward the center of the outer body 12 (see FIG. 1).The apex opposite the base of the triangle lies generally outside, near,or in the direction of the peripheral Wall of the outer body. The edgesor sides of the triangular-shaped intake port or cavity 20 are curved orbowed toward the peripheral wall.

This particular shape for the intake port 26 has been arrived at inexisting engines to a large extent because of certain dimensionalcharacteristics of the rotor it How these characteristics tend todetermine the shape of the intake port will be more fully explainedbelow.

As can be seen most clearly in FIG. 5, means are provided for sealingthe rotor at its apex portions by the sealing members 40, which act asseals between the adjacent working chambers of the engine and which areradially movable within the apex portions 33 to form substantiallycontinuous sliding and gas-sealing contact with the curved peripheralinner surface 18 of the outer body 12.

Means are also provided in the rotor end faces 54 and 56 (FIG. 2) toprovide substantially continuous sliding and gas-sealing contact againstthe inner surface of the end walls 28 and 3d of the outer body 12 as therotor rotates. These latter sealing means can be seen most clearly inFIG. 5, and, as here embodied, they have the form of as trip 58 whichruns continuously along the rotor end face between apex sealing members4%.

These end face gas seals 58, as here preferably embodied, have anL-shaped cross section (as shown in FIG. 4), but could have numerousother shapes, eg, a straight strip or T-shape. In the presentembodiment, the L-shaped cross section provides the beneficial result ofutilizing the gas pressure against the seal to aid in holding thecontact face of the seal against the end wall of the outer body and alsouses gas forces to hold the seal in intimate contact with the insidewall of the sealing slot 60 in the rotor end face.

To complete the means for sealing gases Within the Working chambers, aconnecting seal means 62 is provided at the juncture of the end faceseals 58 and the apex sealing members 40. This connecting sealing means,as here embodied, is in the form of a pin which serves to effectivelyseal the area of contact between the end face seals 58 and the apexsealing members 40. This connecting seal means 62 can be seen mostclearly in FIG. 5.

The basic problem which the present invention solves is illustrated inFIGS. 3 and 4. From a study of FIG. 3 it can be seen that, as normallyconstructed, the closing edge or side 64 of the three-sided intake port2% is virtually coincident with the contour of both the peripheral edgeof the rotor working face 54 and also with the outer periph eral edge ofthe end seal 58 as the seal moves across the closing edge of the intakeport.

FIG. 3 illustrates this condition by showing the relative position ofthe end face seal 58 in line with or almost coincident with the closingedge 64 immediately after the rotor itself has closed or masked theintake port 2%.

Normally, the contour of the closing edge 64 conforms to and iscoincident with the peripheral edge of the working face of the rotor 44to insure that the desideratum of quick closing of the intake port isobtained to the maximum extent possible, after other factors governingthe general configuration of the intake port 2%? have been taken intoconsideration.

The other factors affecting the configuration of the intake port 20 arethe position of the oil seal 66 of the rotor relative to the end faceseals 58, and the position of the connecting seal means 62 with respectto the end wall 28.

As shown in FIGS. 1, 2 and 3, oil sealing means must be provided toprevent the combined lubrication and cooling fluid, which lubricates thebearing means 43 and cools the rotor 10, from running across the rotorend faces 54 and 56 into the working chambers 42. As here embodied, thisoil sealing means comprises an oil seal 66 which circumscribes andencloses the bearing bore rotor 10.

As shown in FIG. 1, it is apparent that the oil seal 66 will be close tothe end face seals 58 in the area between apex portions on the end facesof the rotor, but that it will be further separated from the end faceseals 58 near the apex portions 38 of the rotor end faces. Obviously, toavoid leakage of lubricating and cooling fluid, the intake port 29 mustremain outside of the path described on the inner surface of the endwall by the oil seal as the rotor rotates within the outer body, andthis factor effectively determines the extent to which the inside edgeor base 68 of the triangular-shaped intake port 20 may be moved insidetoward the axis of the outer body. The path described by the oil sealagainst the end face 28, thus, describes the interior limit of theinside edge 68 (see FIG. 3).

Similarly, the requirement that the connecting seal means 62 must be atleast partially supported at all times by the end face 28 to prevent itsprojecting into the intake port 20 is the determining factor in arrivingat the contour for the outside leg or edge 70 of the triangular intakeport. The position of the outside edge 70 may thus be roughly determinedby the path described by the connecting seal 62 against the end face 28as the rotor moves within the outer body 12.

From the foregoing, it is easily realized that the area of the intakeport is definitely restricted in its maximum size by the positions ofthe oil seal 66 and connecting seal 62.

MG. 4 illustrates in an exaggerated manner, for clarity, the deleteriouseffects on both the end face seals 58 and the closing edge 64 of theintake port when the means of the present invention are not provided,and closing of the intake port is accomplished in the usual manner asillustrated in FIG. 3. It can be seen in FIG. 4, that the leading edgeof the end face seal 58 tends to engage the closing edge 64 of theintake port when the closing edge 64 and the end face seal 58 are at ornear a condition of coincidence as they pass each other and as shown inFIG. 3. Although FIG. 4 presents this condition in an exaggeratedmanner, it will be readily apparent from FIG. 4 that even a slightinterference contact between the end face seal 58 and the closing edge64 will have very obvious deleterious effects on both of these parts.

The problem of avoiding excessive wear or damage to the end face seal 58and the closing edge 64 of the intake port because of the bowing out orsinking of the end face seal 58 into the port 20 may' be resolved by aslight but important modification in the contour of the closing edge 64.The possible ways of accomplishing the beneficial results to be achievedfrom the present invention are illustrated in FIG. 5 where the possiblemeans for achieving the invention are depicted in an exaggerated mannerfor clarity of illustration and explanation. By a very slight change inthe contour of the closing edge 64, an interaction and cooperation ofparts is attained that produces new, useful, and beneficial results inthe operation of the engine, and particularly in improving itsreliability, durability, and over-all endurance and performancecharacteristics.

Further, by accomplishing the primary desired object of the instantinvention in minimizing wear and the chances for failure of the end faceseals 58 and closing edge 64 of the intake port by providing for ascissor-like action between the edge and the seal in one particular wayout of the difierent possible ways, an important additional benefit andresult in improved operation of the engine can be obtained. Thisimprovement provides better ignition characteristics, faster and moreconstant flame propagation, and generally smoother operation andimproved combustion.

In accordance with the invention, means are provided to gradually pickup and remove the end face seals 58 from its slightly bowed condition inthe intake port 20 immediately after the commencement of closing of theport, or as the seal engages the edge of the port. As embodied, threepossible means of achieving the desired results of the instant inventionare shown in FIG. 5. The conventional closing edge 64 of the intake portis depicted by a triple dot-dash phantom line.

Also shown in FIG. is a rotor apex portion including the peripheral edgeof one working face of the rotor as it approaches the closing edge 64just prior to covering and closing the intake port. The leading edge 57of the end face seal 58 is shown in broken line coincident with theconventional closing edge 64; this is the position which the leadingedge 57 of the end face seal 53 occupies as the seal passes over theclosing edge of the port, and as described previously and as shown inFIG. 4, presents a condition which can lead to destructive effects onthe seal unless the closing edge 64 is modified.

One means of achieving the result of the present invention, withoutchanging the timing of the intake phase, is depicted by a singledot-dash phantom line in which the end seal 58 is picked up from theinside portion of the outwardly modified closing edge 72 and graduallylifted into its proper place by a scissor-like action as the point ofjuncture between the seal and the edge travels outwardly away from theradially inner portion of the seal. along the outwardly modified closingedge 72. The scissor-like action occurs when the seal and the closingedge Wipe across each other like the two halves of a pair of scissors.This modification of the closing edge slightly, but not materially,reduces the area of the intake port.

A second possible means of accomplishing the benefits of the presentinvention, also without changing the timing of the intake phase, isillustrated by the double dot-dash phantom line in FIG. 5 whichrepresents a further modification of the outward closing edge 72 and isdesignated as 74. This combined outwardly and inwardly modified closingedge 74 of the intake port 20 provides a means by which the end seal 58will be gradually picked up from the port from both ends of the modifiedclosing edge 74 and will be gradually lifted into its proper place bybeing moved both from the outside toward the inside and from the insidetoward the outside so that the last portion of the port to be closedwill be adjacent to an intermediate portion 75 of the modified closingedge 74.

It will be apparent from a study of FIG. 5 that by changing the ratiobetween the lengths of the outside-ta inside portion and theinside-to-outside portion of the modified closing edge 74, the portionof the port which will be last to close in relation to the working face44 of the rotor can be exactly predetermined.

A third possible means for achieving the results of the instantinvention, again without changing the timing of the intake phase, isshown in FIG. 5 by the solid line inwardly modified closing edge contour76. This is the generally preferred means for achieving the instantinvention. Although all three primary forms of the modified closingedge, i.e., edges 72, 74, and 76, slightly reduce the area of the intakeport, the reduction does not have any significant effect on engineoperation.

When this inwardly modified closing edge 76 is used, the end seal 58 ispicked up from the outside portion of the closing edge and is graduallylifted into its proper position in the end face seal slot 60 by ascissor-like action as it travels inwardly away from its outer portionalong the inwardly modified closing edge 76 toward the axis 16 of theouter body 12. Why this latter means of achieving the invention by theinwardly modified closing edge 76 is generally the preferred means foraccomplishing beneficial results of the invention requires furtherexplanation.

Most forms of the rotating combustion engine have a construction suchthat the portion of the working face 44- 'of the rotor 10 which isopposite to or most nearly adjacent to the ignition means 46 at the timeof firing is also the portion of the working face which passes closestto the inside apex 7% of the intake port 20 at or near the time when therotor is closing the port.

It is a well-known characteristic of internal combustion engines thatfuel flow tends to lag air flow during the intake process andaccordingly the last quantity of fuelair mixture to enter the intakechamber is a fuel-rich mixture. If this fuel-rich mixture, which hashighly desirable combustion characteristics, can be placed 0pposite theignition means at the time of firing, the following highly beneficialresults will ensue: better ignition characteristics, faster and moreconstant flame propagation velocity, smoother operation of the engine,and generally improved combustion characteristics.

By using certain preferred means for achieving the present invention, itis possible to essentially localize the terminal enriched intake mixtureand position it adjacent to or opposite the ignition means at the timeof firing. Depending upon the particular construction of the engine,this desideratum can be accomplished by using either the inwardlymodified edge 76 or the inwardly and outwardly modified edge 74- (FIG.5).

Generally, however, for most engines, the inwardly modified edge 76yields the best results, since it localizes the enriched mixture on theworking face 44 in the proper position to place it opposite the ignitionmeans when ignition occurs, and at the same time it provides a simpleand direct means of gradually lifting the end seal 58 into place in therotor 10 upon closing of the intake port 20.

Although in general there is considerable diffusion of the fuel-airmixture within the intake chamber while the intake process is occurring,it will be observed that even before complete closing of the intake port20' by the rotor 10, the compression phase for the chamber begins, i.e.,the rotor 10 has moved past its position of bottom dead center and hasbegun to compress the charge by the time the intake port closes. Also,the engine moves through the compression phase so rapidly that oncecompression starts, the combustible mixture does not becomesubstantially further diffused or dispersed because the inertia of themixture itself is high compared to the time period of the compressionphase. Probably because of the facts just mentioned, the fuel-richmixture which enters the intake chamber last, if it enters from theinside apex of the intake port, tends to remain localized in itsposition with respect to the working face 44 of the rotor at least untilthe rotor has moved into firing position and placed this fuel-richmixture opposite the ignition means. This is another reason why theinwardly modified closing edge 76 is considered the preferred means ofachieving the inst-ant invention.

Although the outwardly modified closing edge 72. is just as desirable asthe inwardly modified edge 76 from the standpoint of smoothly guidingthe end seal 58 back into sealing contact with the end wall 28, it doesnot provide the unusual interaction and cooperation of parts which arederived by using the inwardly modified closing edge 76 (or for someconstructions of the engine the outwardly and inwardly modified closingedge 74). The inwardly modified closing edge 76, thus, provides thecombination of smoothly guiding the end seal 58 back into contact withthe end wall 28 while at the same time it localizes the enrichedterminal intake mixture in the desired position on the working face 44of the rotor 10. It can be seen in FIG. 5 that in one sense the inwardlymodified closing edge 76 may be created by employing a contour for theedge which will insure that the edge will be inclined to each end faceseal 58 throughout a major length of the edge as the seal moves over theedge.

This difference in inclination should not be great, however, since it isdesirable from a combustion standpoint to have the closing edge of theintake port 20 and the end seal 58 fairly close in contour to preservethe desired timing for the intake phase without substantially alteringthe area of the intake port. It is also very desirable to preserve asnearly as possible the quick-closing characteristic for the intake port.

The inclination of the closing edge must, however, be suflicient to giveadequate lifting action against the end face seal 58. In one embodimentof the engine, the angle of inclination between the closing edge and theend face seal 58, when using the inwardly modified closing edge 76, hasa value of 25 as the seal 58 first comes into contact with the edge 76,and this angle between the edge and the seal is gradually reduced to bythe time this seal passes over the port. Of course, the angle betweenthe seal and the edge could vary considerably and one of the primaryobjects of the invention, scissor action between the seal and edge,could still be achieved.

The present invention relates to the discovery that by a slight butunobvious mechanical change in the construction of the rotatingcombustion engine, or other rotary mechanisms, it is possible to achievea very important combination of unexpected beneficial results. Thisachievement is accomplished by providing an inwardly closing modifiededge for the intake port to greatly improve end seal performance and atthe same time to provide better ignition, flame propagation, combustion,and smooth operating characteristics for the engine.

This invention in its broader aspects is not limited to the specificmechanisms shown and described, but also includes within the scope ofthe accompanying claims any departures made from such mechanisms whichdo not depart from the principles of the invention and which do notsacrifice its chief advantages.

What is claimed is:

1. A rotary mechanism comprising a hollow outer body having an axis,axially-spaced end walls, and a peripheral wall interconnecting the endwalls, at least one of the end walls having an intake port meanstherein; a rotor mounted within the outer body on m axis eccentric tothe axis of the outer body and rotatable relative to the outer body, therotor having end faces disposed adjacent to the end walls and aplurality of circumferentiallyspaced apex portions for sliding insealing engagement with the inner surface of the peripheral wall to forma plurality of working chambers between the rotor and peripheral wallthat vary in volume upon relative rotation of the rotor within the outerbody, sealing means extending along the end faces of the rotor betweenthe apex portions in sealing contact with the end walls, ignition meansin operative association with the working chambers, a carburetor thatsupplies a fuel-air mixture to the working chambers of the enginethrough the intake port, the fuel-air mixture becoming increasingly richfrom the beginning to the end of intake in any one working chamber, therotor also having Working faces interconnecting apex portions andextending from one apex portion to an adjacent apex portion, the closingedge contour of the intake port means being inclined to the edge of theworking face of the rotor as the working face of the rotor moves overthe closing edge, whereby the portion of the fuel-air mixture richest infuel has an extent less than the extent of the closing edge contour andremains contiguous in the working chamber to the area of the workingface that is adjacent the ignition means at the time of 'firing.

2. The invention as defined in claim 1, in which the edge of the sealingmeans is substantially parallel to the edge of the adjacent working faceof the rotor, and in which the closing edge is so inclined to the edgeof the adjacent working face of the rotor that the port closes in adirection outwardly from the axis of the outer body.

3. The invention as defined in claim 1, in which the edge of the sealingmeans is substantially parallel to the edge of the adjacent working faceof the rotor, and in which the closing edge is so inclined to the edgeof the adjacent working face of the rotor that the port closes in adirection'inwardly toward the axis of the outer body.

References Cited in the file of this patent UNITED STATES PATENTS1,636,486 Planche July 19, 1927 2,947,290 Froede Aug. 21, 1960 2,988,065Wankel et a1. June 13, 1961 FOREIGN PATENTS 17,248 Great Britain 1901

1. A ROTARY MECHANISM COMPRISING A HOLLOW OUTER BODY HAVING AN AXIS,AXIALLY-SPACED END WALLS, AND A PERIPHERAL WALL INTERCONNECTING THE ENDWALLS, AT LEAST ONE OF THE END WALLS HAVING AN INTAKE PORT MEANSTHEREIN; A ROTOR MOUNTED WITHIN THE OUTER BODY ON AN AXIS ECCENTRIC TOTHE AXIS OF THE OUTER BODY AND ROTATABLE RELATIVE TO THE OUTER BODY, THEROTOR HAVING END FACES DISPOSED ADJACENT TO THE END WALLS AND APLURALITY OF CIRCUMFERENTIALLYSPACED APEX PORTIONS FOR SLIDING INSEALING ENGAGEMENT WITH THE INNER SURFACE OF THE PERIPHERAL WALL TO FORMA PLURALITY OF WORKING CHAMBERS BETWEEN THE ROTOR AND PERIPHERAL WALLTHAT VARY IN VOLUME UPON RELATIVE ROTATION OF THE ROTOR WITHIN THE OUTERBODY, SEALING MEANS EXTENDING ALONG THE END FACES OF THE ROTOR BETWEENTHE APEX PORTIONS IN SEALING CONTACT WITH THE END WALLS, IGNITION MEANSIN OPERATIVE ASSOCIATION WITH THE WORKING CHAMBERS, A CARBURETOR THATSUPPLIES A FUEL-AIR MIXTURE TO THE WORKING CHAMBERS OF THE ENGINETHROUGH THE INTAKE PORT, THE FUEL-AIR MIXTURE BECOMING INCREASINGLY RICHFROM THE BEGINNING TO THE END OF INTAKE IN ANY ONE WORKING CHAMBER, THEROTOR ALSO HAVING WORKING FACES INTERCONNECTING APEX PORTIONS ANDEXTENDING FROM ONE APEX PORTION TO AN ADJACENT APEX PORTION, THE CLOSINGEDGE CONTOUR OF THE INTAKE PORT MEANS BEING INCLINED TO THE EDGE OF THEWORKING FACE OF THE ROTOR AS THE WORKING FACE OF THE ROTOR MOVES OVERTHE CLOSING EDGE, WHEREBY THE PORTION OF THE FUEL-AIR MIXTURE RICHEST INFUEL HAS AN EXTENT LESS THAN THE EXTENT OF THE CLOSING EDGE CONTOUR ANDREMAINS CONTIGUOUS IN THE WORKING CHAMBER TO THE AREA OF THE WORKINGFACE THAT IS ADJACENT THE IGNITION MEANS AT THE TIME OF FIRING.